def test_get_age(self):
"""
test to obtain the age of the students to calculate the average age
"""
today = date.today()
year = 1991
day_before = date(year=year, month=today.month, day=today.day-1)
day_today = date(year=year, month=today.month, day=today.day)
day_after = date(year=year, month=today.month, day=today.day+1)
age_full = today.year - year
age_not_full = today.year - year - 1
department_serializer = DepartmentSerializer()
day_before_get = department_serializer.get_age(day_before)
self.assertEqual(age_full, day_before_get)
day_today_get = department_serializer.get_age(day_today)
self.assertEqual(age_full, day_today_get)
day_after_get = department_serializer.get_age(day_after)
self.assertEqual(age_not_full, day_after_get)
